Cooling device for removing heat from subcutaneous lipid-rich cells

ABSTRACT

A cooling device for removing heat from subcutaneous lipid-rich cells of a subject having skin is provided. The cooling device includes a support having a first portion and a second portion. A first cooling element having a first heat exchanging surface is located at the first portion of the support. A second cooling element having a second heat exchanging surface is located at the second portion of the support. At least one of the first and second cooling elements is movable along the support and is configured to rotate for adjusting an angle between the first and second heat exchanging surfaces.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of U.S. patent application Ser.No. 11/359,092, now U.S. Pat. No. 7,854,754, filed Feb. 22, 2006, thedisclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates to cooling devices, systems, and methodsfor removing heat from subcutaneous lipid-rich cells.

BACKGROUND

As statistics have shown, excess body fat increases the likelihood ofdeveloping various types of diseases such as heart disease, high bloodpressure, osteoarthrosis, bronchitis, hypertension, diabetes, deep-veinthrombosis, pulmonary emboli, varicose veins, gallstones, hernias, andseveral other conditions.

In addition to being a serious health risk, excess body fat can alsodetract from personal appearance and athletic performance. For example,excess body fat can form cellulite that causes an “orange peel” effectat the surface of the skin. Cellulite forms when subcutaneous fatprotrudes into the dermis and creates dimples where the skin is attachedto underlying structural fibrous strands. Cellulite and excessiveamounts of fat are often considered to be unappealing. Thus, in light ofthe serious health risks and aesthetic concerns associated with excessfat, an effective way of controlling excess accumulation of body fat isurgently needed.

Liposuction is a method for selectively removing body fat to sculpt aperson's body. Liposuction is typically performed by plastic surgeonsusing specialized surgical equipment that mechanically removessubcutaneous fat cells via suction. One drawback of liposuction is thatit is a serious surgical procedure, and the recovery may be painful.Liposuction can have serious and occasionally even fatal complications.In addition, the cost for liposuction is usually substantial.

Conventional non-invasive treatments for removing excess body fattypically include topical agents, weight-loss drugs, regular exercise,dieting, or a combination of these treatments. One drawback of thesetreatments is that they may not be effective or even possible undercertain circumstances. For example, when a person is physically injuredor ill, regular exercise may not be an option. Similarly, weight-lossdrugs or topical agents are not an option when they cause an allergic ornegative reaction. Furthermore, fat loss in selective areas of aperson's body cannot be achieved using weight-loss drugs.

Other non-invasive treatment methods include applying heat to a zone ofsubcutaneous lipid-rich cells. U.S. Pat. No. 5,948,011 disclosesaltering subcutaneous body fat and/or collagen by heating thesubcutaneous fat layer with radiant energy while cooling the surface ofthe skin. The applied heat denatures fibrous septa made of collagentissue and may destroy fat cells below the skin, and the coolingprotects the epidermis from thermal damage. This method is less invasivethan liposuction, but it still can cause thermal damage to adjacenttissue.

Another promising method of reducing subcutaneous fat cells is to coolthe target cells as disclosed in U.S. Patent Publication No.2003/0220674, the entire disclosure of which is incorporated herein.This publication discloses, among other things, reducing the temperatureof lipid-rich subcutaneous fat cells to selectively affect the fat cellswithout damaging the cells in the epidermis. Although this publicationprovides promising methods and devices, several improvements forenhancing the implementation of these methods and devices would bedesirable.

U.S. Patent Publication No. 2003/0220674 also discloses methods forselective removal of lipid-rich cells, and avoidance of damage to otherstructures including dermal and epidermal cells. A method for inducingcollagen compaction, remodeling and formation is also needed fortreatment of loose or sagging skin, age- or sun-damaged skin or avariety of other skin disorders. Therefore, a method for simultaneouslyremoving lipid-rich cells while providing beneficial collagen effects isalso needed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a system for removing heat fromsubcutaneous lipid-rich cells in accordance with an embodiment of theinvention.

FIGS. 2A, 2B and 2C are isometric views of a cooling device for removingheat from subcutaneous lipid-rich cells in accordance with embodimentsof the invention.

FIG. 3A is an end view and FIG. 3B is a side cross-sectional viewpartially illustrating a cooling device for removing heat fromsubcutaneous lipid-rich cells in accordance with an embodiment of theinvention.

FIG. 4 is a side elevation view illustrating a cooling device havingthermoelectric cooling elements in accordance with another embodiment ofthe invention.

FIGS. 5A and 5B are side elevation views of a cooling device havingcurved heat exchanging surfaces in accordance with another embodiment ofthe invention.

FIG. 6 is a block diagram showing computing system software modules forremoving heat from subcutaneous lipid-rich cells.

DETAILED DESCRIPTION

A. Overview

The present disclosure describes devices, systems, and methods forcooling subcutaneous lipid-rich cells. The term “subcutaneous tissue”means tissue lying underneath the dermis and includes adipocytes (fatcells) and subcutaneous fat. It will be appreciated that several of thedetails set forth below are provided to describe the followingembodiments in a manner sufficient to enable a person skilled in therelevant art to make and use the disclosed embodiments. Several of thedetails and advantages described below, however, may not be necessary topractice certain embodiments of the invention. Additionally, theinvention can include other embodiments that are within the scope of theclaims but are not described in detail with respect to FIGS. 1-6.

One aspect is directed toward a cooling device for removing heat fromsubcutaneous lipid-rich cells. The cooling device includes a supportwith a first portion and a second portion, a first cooling elementhaving a first heat exchanging surface, and a second cooling elementhaving a second heat exchanging surface. The first cooling element islocated at the first portion of the support, and the second coolingelement is located at the second portion of the support. At least one ofthe first and second cooling elements is movable along the support, andat least one of the first and second cooling elements is configured torotate for adjusting an angle between the first and second heatexchanging surfaces. The first and second cooling elements, for example,can be rotatable either in two dimensions or in three dimensions. Thecooling elements can use a number of cooling technologies includingthermoelectric coolers, recirculating chilled fluid, vapor compressionelements, or phase change cryogenic devices. One skilled in the art willrecognize that there are a number of other cooling technologies thatcould be used and that the cooling elements need not be limited to thosedescribed here. Further aspects include that the cooling device can beconfigured as a handheld device.

Another aspect is directed toward a cooling device having a coolingmember using thermoelectric principles or other cooling technologies.The cooling device also includes a heat dissipating member in thermalcommunication with the cooling member and an interface member having aheat exchanging surface configured to contact a subject's skin. Thecooling member can be capable of reducing a temperature of a region suchthat lipid-rich cells in the region are affected while non-lipid-richcells are not generally affected. Further aspects include that the heatexchanging surface can be a curved surface for concentrating the coolingeffects.

Another aspect is directed toward a method of applying a cooling devicehaving two cooling elements rotatable relative to each other. Thecooling elements can have heat exchanging surfaces capable of removingheat from the subject's skin. The method includes rotating the coolingelements to achieve a desired orientation between the two heatexchanging surfaces, cooling the heat exchanging surfaces of the twocooling elements to a desired temperature, placing the cooled heatexchanging surfaces proximate to the subject's skin, and reducing atemperature of a region such that lipid-rich cells in the region areaffected while non-lipid-rich cells in the epidermis are not generallyaffected. Further aspects include holding the cooling device by at leastone hand of an operator.

Another aspect is directed toward a system for removing heat fromsubcutaneous lipid-rich cells. The system includes a cooling devicehaving two rotatable cooling elements capable of achieving a desiredorientation between each other, and a heat sink coupled to the coolingdevice to dissipate heat generated by the cooling device. When placedproximate to a subject's skin, the two cooling elements can be capableof reducing a temperature of a region such that lipid-rich cells in theregion are affected while non-lipid-rich cells in the epidermis and/ordermis are not generally affected. Further aspects include that thecooling device can be configured as a handheld device.

B. System for Selectively Reducing Lipid-rich Cells

FIG. 1 is an isometric view of a system 100 for removing heat fromsubcutaneous lipid-rich cells of a subject 101 in accordance with anembodiment of the invention. The system 100 can include a cooling device104 placed at an abdominal area 102 of the subject 101 or anothersuitable area for removing heat from the subcutaneous lipid-rich cellsof the subject 101. Various embodiments of the cooling device 104 aredescribed in more detail below with reference to FIGS. 2-5.

The system 100 can further include a cooling unit 106 and fluid lines108 a-b connecting the cooling device 104 to the cooling unit 106. Thecooling unit 106 can remove heat from a coolant to a heat sink andprovide the chilled coolant to the cooling device 104 via the fluidlines 108 a-b. Examples of the circulating coolant include water,glycol, synthetic heat transfer fluid, oil, a refrigerant and any othersuitable heat conducting fluids. The fluid lines 108 a-b can be hoses orother conduits constructed from polyethylene, polyvinyl chloride,polyurethane, and other materials that can accommodate the particularcirculating coolant. The cooling unit 106 can be a refrigeration unit, acooling tower, a thermoelectric chiller, or any other device capable ofremoving heat from a coolant.

As explained in more detail below, the cooling device 104 can includeone or more thermoelectric cooling elements, such as Peltier-typethermoelectric elements. In such cases, the system 100 can furtherinclude a power supply 110 and a processing unit 114 operatively coupledto the cooling device 104. In one embodiment, the power supply 110 canprovide a direct current voltage to the cooling device 104 to effectuatea heat removal rate from the subject 101. The processing unit 114 canmonitor process parameters via sensors (not shown) placed proximate tothe cooling device 104 and adjust the heat removal rate based on theprocess parameters. The processing unit 114 can include any processor,Programmable Logic Controller, Distributed Control System, and the like.

In another aspect, the processing unit 114 can be in electricalcommunication with an input device 118, an output device 120, and/or acontrol panel 122. The input device 118 can include a keyboard, a mouse,a touch screen, a push button, a switch, a potentiometer, and any otherdevices suitable for accepting user input. The output device 120 caninclude a display screen, a printer, a medium reader, an audio device,and any other devices suitable for providing user feedback. The controlpanel 122 can include indicator lights, numerical displays, and audiodevices. In the embodiment shown in FIG. 1, the processing unit 114,power supply 110, control panel 122, cooling unit 106, input device 118,and output device 120 are carried by a rack 124 with wheels 126 forportability. In another embodiment, the various components can befixedly installed at a treatment site.

One expected advantage of the system 100 is that the cooling device 104can be applied to the subject 101 irrespective of the current physicalcondition of the subject 101. For example, the system 100 can be appliedeven when the subject 101 is not ambulatory or is ill. Another expectedadvantage is that the system 100 can remove or affect fat non-invasivelywithout piercing the skin of the subject 101. Yet another expectedadvantage is that the system 100 is compact and can be used in anoutpatient facility or a doctor's office. A further expected advantageis that the system 100 can quickly cool lipid-rich cells in asubcutaneous layer without requiring high-voltage power supplies.

C. Cooling Devices with Rotatable Cooling Elements

FIG. 2A is an isometric view of a cooling device 104 in accordance withone example of the invention suitable for use in the system 100. In thisexample, the cooling device 104 includes a support 128 having a firstportion 129 a and a second portion 129 b, a first cooling element 130 alocated at the first portion 129 a, and a second cooling element 130 blocated at the second portion 129 b. The cooling device 104 is generallyconfigured to be a handheld unit for manual operation, and/or it can bestrapped or otherwise configured to be releasably attached to thesubject. The first cooling element 130 a and/or the second coolingelement 130 b can be configured to move along the support 128 and/orrotate to position the cooling elements 130 a-b for applying pressure tothe treatment area during operation. These features are described inmore detail below with reference to specific examples of the coolingdevices.

The first and second cooling elements 130 a-b can have many similarfeatures. As such, the features of the first cooling element 130 a aredescribed below with reference symbols followed by an “a”, andcorresponding features of the second cooling element 130 b are shown andnoted by the same reference symbol followed by a “b.” The first coolingelement 130 a can include a housing 139 a and fluid ports 138 a-bcoupled to the fluid lines 108 a-b. The housing 139 a can be constructedfrom polymeric materials, metals, ceramics, woods, and/or other suitablematerials. The example of the housing 139 a shown in FIG. 2A isgenerally rectangular but it can have any other desired shape.

The first cooling element 130 a can further include a first interfacemember 132 a having a first heat exchanging surface 131 a fortransferring heat to/from the subject 101. In one example, the firstheat exchanging surface 131 a is generally planar, but in otherexamples, the first heat exchanging surface 131 a is non-planar (e.g.,curved, faceted, etc.) The first interface member 132 a can beconstructed from any suitable material with a thermal conductivitygreater than 0.05 Watts/Meter ° Kelvin, and in many examples, thethermal conductivity is more than 0.1 Watts/Meter ° Kelvin. Examples ofsuitable materials include aluminum, other metals, metal alloys,graphite, ceramics, some polymeric materials, composites, or fluidscontained in a flexible membrane. As further described below withreference to FIGS. 4 and 5, portions of the first heat exchangingsurface 131 a can be an insulating material with a thermal conductivityless than 0.05 Watts/Meter ° Kelvin.

The first cooling element 130 a can also include at least one sensingelement 135 a proximate to the first heat exchanging surface 131 a. Thesensing element 135 a, for example, can be generally flush with the heatexchanging surface 131 a. Alternatively, it may be recessed or protrudefrom the surface. The sensing element 135 a can include a temperaturesensor, a pressure sensor, a transmissivity sensor, a bio-resistancesensor, an ultrasound sensor, an optical sensor, an infrared sensor, orany other desired sensor. In one example, the sensing element 135 a canbe a temperature sensor configured to measure the temperature of thefirst heat exchanging surface 131 a and/or the temperature of the skinof the subject 101. For example, the temperature sensor can beconfigured as a probe or as a needle that penetrates the skin duringmeasurement. Examples of suitable temperature sensors includethermocouples, resistance temperature devices, thermistors (e.g.,neutron-transmutation-doped germanium thermistors), and infraredradiation temperature sensors. In another example, the sensing element135 a can be an ultrasound sensor configured to measure crystallizationof subcutaneous fat in the treatment region of a subject. In yet anotherexample, the sensing element 135 a can be an optical or infrared sensorconfigured to monitor an image of the treatment region to detect, forexample, epidermal physiological reactions to the treatment. The sensingelement 135 a can be in electrical communication with the processingunit 114 via, for example, a direct wired connection, a networkedconnection and/or a wireless connection.

The cooling device 104 can further include a mounting element 136 a thatcouples the first cooling element 130 a to the first portion 129 a ofthe support 128. The mounting element 136 a, for example, can be a pin,a ball joint, a bearing, or other types of rotatable joints. Suitablebearings include, but are not limited to, ball bearings, rollerbearings, thrust bearings, and journal bearings. The mounting element136 a can accordingly be configured to rotatably couple the firstcooling element 130 a to the support 128. In certain embodiments, thefirst cooling element 130 a can rotate relative to the support 128 intwo dimensions (indicated by arrow A) such that the angle between thefirst and second heat exchanging surfaces 131 a-b can be adjusted. Inanother embodiment, the first cooling element 130 a can rotate in threedimensions relative to the support 128 (as indicated by arrows A and B).

A specific example of the mounting element 136 a includes a firstmounting base 134 a and a flange 137 a coupled to the base 134 a by arotatable or pivotable joint. By rotatably mounting at least one of thefirst and second cooling elements 130 a-b to the support 128, the anglebetween the first and second heat exchanging surfaces 131 a-b can beadjusted. For example, as shown in FIG. 2A, the first and second coolingelements 130 a-b can be generally parallel to each other, i.e., have anangle of generally 0° between the first and second heat exchangingsurfaces 131 a-b. As shown in FIG. 2B, the first and second coolingelements 130 a-b can be generally co-planar, i.e., have an angle ofgenerally 180° between the first and second heat exchanging surfaces 131a-b. With the rotatable mounting elements 136 a-b, any angle of about 0°to about 180° between the first and second heat exchanging surfaces 131a-b can be achieved.

The cooling device 104 can further include a shaft 133, and the firstmounting base 134 a can be attached to the shaft 133. As explained inmore detail below, at least one of the cooling elements 130 a-b movesalong the shaft 133 and/or the shaft 133 moves relative to the support128 to adjust the distance between the first and second cooling elements130 a-b (shown by arrow C). The shaft 133, more specifically, extendsbetween the first and second cooling elements 130 a-b to enable movementof at least one of the cooling elements 130 a-b relative to the support128. In the embodiment shown in FIG. 2A, the first mounting base 134 ais fixedly attached to the shaft 133, and a second mounting base 134 bof the second cooling element 130 b is configured such that the secondmounting base 134 b can slide along the shaft 133. In other embodiments,both the first mounting base 134 a and the second mounting base 134 bcan be configured to slide along the shaft 133. The shaft 133 isgenerally constructed from polymeric materials, metals, ceramics, woods,or other suitable materials.

The cooling device 104 further includes a handle 140 slidably coupled tothe shaft 133 or formed as a part of the shaft 133. The handle 140 isconfigured to be held by a hand of an operator. For example, the handle140 can have a grip with grooves to improve stability of the coolingdevice 104 when held by the operator. The handle 140 further includes anactuator 142 that operates with the shaft 133 to move the second coolingelement 130 b relative to the shaft 133. In the example shown in FIG.2A, the actuator 142 is a lever that engages the shaft 133 toincrementally advance the second cooling element 130 b in an axialmotion (arrow C) along the shaft 133.

In operation, an operator can hold the cooling device 104 in one hand bygrasping the handle 140. Then, the cooling elements 130 a-b can berotated via the mounting elements 136 a-b to achieve a desiredorientation. The operator can place the cooling device 104 having thecooling elements 130 a-b in the desired orientation proximate to thesubject's skin to remove heat from a subcutaneous region of the subject101. In one embodiment, the operator can clamp a portion of thesubject's skin between the heat exchanging surfaces 131 a-b when thesurfaces 131 a-b are generally parallel to each other. In anotherembodiment, the operator can press the heat exchanging surfaces 131 a-bagainst the subject's skin when the surfaces 131 a-b are generallyco-planar. In certain embodiments, the operator can use thermoelectriccoolers to remove heat from the subcutaneous region as described belowwith reference to FIG. 4. The operator can also monitor and control thetreatment process by collecting measurements, such as skin temperatures,from the sensing element 135 a. By cooling the subcutaneous tissues to atemperature lower than 37° C., subcutaneous lipid-rich cells can beselectively affected. The affected cells are then resorbed into thepatient through natural processes.

One expected advantage of using the cooling device 104 is thatsubcutaneous lipid-rich cells can be reduced generally withoutcollateral damage to non-lipid-rich cells in the same region. Ingeneral, lipid-rich cells can be affected at low temperatures that donot affect non-lipid-rich cells. As a result, lipid-rich cells, such asthose forming the cellulite, can be affected while other cells in thesame region are generally not damaged even though the non-lipid-richcells at the surface are subject to even lower temperatures. Anotherexpected advantage of the cooling device 104 is that it is relativelycompact because the cooling device 104 can be configured as a handhelddevice. Yet another advantage is that the cooling device can be appliedto various regions of the subject's body because the two coolingelements 130 a-b can be adjusted to conform to any body contour. Anotherexpected advantage is that by pressing the cooling device 104 againstthe subject's skin, blood flow through the treatment region can bereduced to achieve efficient cooling. Still another expected advantageis that the power requirement is reduced for each of the coolingelements 130 a-b because heat is removed from the skin through the twoheat exchanging surfaces 131 a-b instead of a single cooling element.

The first and second cooling elements 130 a-b can have many additionalembodiments with different and/or additional features without detractingfrom the operation of both elements. For example, the second coolingelement 130 b may or may not have a sensing element proximate to thesecond heat exchanging surface 131 b. The second cooling element 130 bcan be constructed from a material that is different from that of thefirst cooling element 130 a. The second mounting base 134 b can have ashape and/or a surface configuration different from that of the firstmounting base 134 a. The first cooling element 130 a can be rotatable,but the second cooling element 130 b may be non-rotatable.

FIG. 2C is an alternative example of the cooling device 104 inaccordance with one example of the invention for use in the system 100.This alternative example, and those alternative examples and otheralternatives described herein, are substantially similar topreviously-described examples, and common acts and structures areidentified by the same reference numbers. Only significant differencesin operation and structure are described below. In this example, thecooling device 104 includes a support 128 having a portion 129 b and aportion 160, a cooling element 130 b located at the portion 129 b, and areciprocating element 164 located at the portion 160. The cooling device104 is generally configured to be a handheld unit for manual operation,and/or it can be strapped or otherwise configured to be releasablyattached to the subject. In this example, the reciprocating element 164can be configured to move along the support 128 and/or rotate toposition the reciprocating element 164 to apply pressure to thetreatment area during operation. The reciprocating element 164 caninclude a housing 166 and a sensing element 162. The housing 166 can beconstructed from polymeric materials, metals, ceramics, woods, and/orother suitable materials. The example of the housing 166 shown in FIG.2C is generally rectangular, but can have any other desired shape.

The reciprocating element 164 can also include at least one sensingelement 162 proximate to the skin (not shown). The sensing element 162,for example, can be generally flush with a face of the reciprocatingelement 164. Alternatively, it may be recessed or protrude from thesurface. The sensing element 162 can include a temperature sensor, apressure sensor, a transmissity sensor, a bioresistance sensor, anultrasound sensor, an optical sensor, an infrared sensor, or any otherdesired sensor, as discussed in detail herein.

FIG. 3A is an end view and FIG. 3B is a side elevation view of theembodiment of the cooling device 104 shown in FIGS. 2A and 2B. Likereference symbols refer to like features and components in FIGS. 1-3B.In one aspect, the first cooling element 130 a can include a fluidchamber 150 a within the housing 139 a. The fluid chamber 150 a can bein fluid communication with the fluid ports 138 a-b such that fluid cancirculate through the fluid chamber 150 a. Optionally, the fluid chamber150 a can include one or more flow elements to promote uniform orotherwise controlled fluid circulation through the fluid chamber 150 a.For example, the fluid chamber 150 a can include baffles, static mixers,nozzles, ventures, orifices or any combination of these flow elements.The fluid chamber 150 a can be configured to accept fluid coolants, suchas water, glycol, a synthetic heat transfer fluid, oil, refrigerants,air, carbon dioxide, nitrogen, and argon.

The first interface member 132 a can be a diffuser disposed in thehousing 139 a such that the first heat exchanging surface 131 a facesaway from the fluid chamber 150 a. The first interface member 132 a isaccordingly in thermal communication with the fluid chamber 150 a totransfer heat between the first heat exchanging surface 131 a and thefluid chamber 150 a. In one embodiment, the interface member 132 a isreleasably attached to the housing 139 a using mechanical fasteners toallow access to the fluid chamber 150 a or the backside of the firstinterface member 132 a. The sensing element 135 a can be placed in thefirst interface member 132 a at least proximate to the first heatexchanging surface 131 a as described above.

The first cooling element 130 a can also include a pressure sensor 152between the housing 139 a and the mounting element 136 a to sense thepressure exerted by the first cooling element 130 a against the subject.In one embodiment, the first interface member 132 a can be attached tothe housing such that pressure applied against the first heat exchangingsurface 131 a is transferred via the housing 139 a to the pressuresensor 152. The pressure sensor 152 can alternatively be configured tosense the pressure in the fluid chamber 150 a for monitoring pressurevariations in the fluid chamber 150 a. Alternatively, the pressure couldbe inferred from force and the known contact area of the coolingelements. For example, the sensor 152 can be any type of load-sensitivepressure sensing element such as a load cell (model #LC201-25) producedby OMEGA Engineering, Inc. in Stamford, Conn. Direct pressuremeasurement could also be performed by placing a pressure measurementmembrane directly at the interface between the cooling element and theskin.

The second cooling element 130 b can also include a second interfacemember 132 b similar to that of the first cooling element 130 a. Asshown in FIG. 3B, the second interface member 132 b does not have asensing element proximate to the second heat exchanging surface 131 b.However, the second cooling element 130 b can include a temperaturesensor and/or a pressure sensor similar to the first cooling element 130a. In addition, the first and second cooling elements 130 a-b can beconfigured to have different sensing elements.

FIG. 3B illustrates additional aspects of an example of the handle 140and actuator 142. The actuator 142 can further include a spring 146 thatdrives the lever against a stop 147 fixedly attached to the secondmounting base 134 b. In operation, when an operator moves the actuator142 toward the handle 140, the actuator 142 overcomes the force from thespring 146 to move the second mounting base 134 b along the shaft 133toward the first mounting base 134 a. When the operator releases theactuator 142, the spring 146 drives the actuator 142 back in contactwith the stop 147.

The cooling device 104 can further include a locking element thatreleasably holds the first and second cooling elements 130 a-b in afixed relative position. The locking element can be a catch 144 having aslot 143 through which the shaft 133 extends. A locking spring 145forces the catch 144 to be at an angle relative to the shaft 133 suchthat the catch 144 frictionally engages the shaft 133. In operation,when an operator moves the actuator 142 toward the handle 140, the shaft133 overcomes the force from the locking spring 145 to move the secondmounting base 134 b toward the first mounting base 134 a. When theoperator releases the actuator 142, the locking spring 145 drives thecatch 144 away from the actuator 142 such that the catch 144 re-engagesthe shaft 133 to prevent the shaft 133 from slidably moving through theslot 143. When the operator moves the catch 144 toward the handle 140,the catch 144 disengages the shaft 133 to allow the shaft 133 to slidethrough the slot 143 so that the second cooling element 130 b can bemoved away from the first cooling element 130 a. When the operatorreleases the catch 144, it re-engages the shaft 133 to prevent the shaft133 from moving.

D. Method of Applying Cooling Devices With Rotatable Cooling Elements

In operation, the angle between the first and second heat exchangingsurfaces 131 a-b is selected by rotating the first and second coolingelements 130 a-b. The angle between the cooling elements 130 a-b isoften selected to conform the first and second heat exchanging surfaces131 a-b to various body contours of the subject 101 and/or a desiredclamping arrangement. In the embodiment shown in FIG. 2A, the anglebetween the first and second heat exchanging surfaces 131 a-b can begenerally 0°, i.e., the first and second heat exchanging surfaces 131a-b are generally parallel to each other for clamping a treatment regionbetween the first and second cooling elements 130 a-b. In the embodimentshown in FIG. 2B, the angle can be 180°, i.e., the first and second heatexchanging surfaces 131 a-b are generally co-planar. In otherembodiments, the angle can be any angle between generally 0° andgenerally 180°, as would be recognized by one skilled in the art.

After configuring the cooling elements 130 a-b, an operator places thecooling device 104 proximate to the skin of the subject 101. In theembodiment shown in FIG. 2A (where the angle is generally 0°), thecooling elements 130 a-b are initially spaced apart from each other by afirst distance in which a fold of the patient's skin is placed. Theoperator then pulls the actuator 142 to drive the second cooling element130 b toward the first cooling element 130 a until the fold of skin isclamped between the cooling elements 130 a-b. The clamping force can beincreased by using the actuator 142 or decreased by disengaging thecatch 144. Optionally, the pressure sensor 152 can be used to sense theclamping pressure applied via the first interface member 132 a, and thesensed clamping force can be processed by the processing unit 114 anddisplayed on the output device 120. The clamping force can then beadjusted based on the displayed values. The clamping force, for example,can be higher than the systolic pressure in the fold of skin to impedeor block the blood flow into the fold of skin. As explained in moredetail below, applying such pressure enables more effective cooling ofthe target region because there is less blood flow to transfer core bodyheat to the target region.

In another embodiment shown in FIG. 2B (where the angle is generally180°), placing the cooling device 104 can include pressing the first andsecond heat exchanging surfaces 131 a-b against an area of the subject'sskin. In one aspect, the applied pressure on the subject's skin can begreater than or equal to the systolic blood pressure in the subject'sskin. Optionally, the pressure sensor 152 can be used to sense thepressure applied via the first interface member 132 a, and the pressureapplied to the subject's skin can be adjusted as described above.

Clamping a fold of the subject's skin or pressing against the skin canbe advantageous to achieve efficient cooling. In general, the subject101 has a body temperature of about 37° C., and the blood circulation isone mechanism for maintaining a constant body temperature. As a result,blood flow through the dermis and subcutaneous layer of the region is aheat source that counteracts the cooling of the sub-dermal fat. As such,if the blood flow is not reduced, cooling the subcutaneous tissues wouldrequire not only removing the specific heat of the tissues but also thatof the blood circulating through the tissues. Thus, reducing oreliminating blood flow through the target region can improve theefficiency of cooling and avoid excessive heat loss from the dermis andepidermis.

By cooling the subcutaneous tissues to a temperature lower than 37° C.,subcutaneous lipid-rich cells can be selectively affected. In general,the epidermis and dermis of the subject 101 have lower amounts ofunsaturated fatty acids compared to the underlying lipid-rich cellsforming the subcutaneous tissues. Because non-lipid-rich cells usuallycan withstand colder temperatures better than lipid-rich cells, thesubcutaneous lipid-rich cells can be selectively affected whilemaintaining the non-lipid-rich cells in the dermis and epidermis. Anexemplary range for the cooling elements 130 a-b can be from about −20°C. to about 20° C., preferably from about −20° C. to about 10° C., morepreferably from about −15° C. to about 5° C., more preferably from about−10° C. to about 0° C.

The lipid-rich cells can be affected by disrupting, shrinking,disabling, destroying, removing, killing, or otherwise being altered.Without being bound by theory, selectively affecting lipid-rich cells isbelieved to result from localized crystallization of highly saturatedfatty acids at temperatures that do not induce crystallization innon-lipid-rich cells. The crystals can rupture the bi-layer membrane oflipid-rich cells to selectively necrose these cells. Thus, damage ofnon-lipid-rich cells, such as dermal cells, can be avoided attemperatures that induce crystal formation in lipid-rich cells. Coolingis also believed to induce lipolysis (e.g., fat metabolism) oflipid-rich cells to further enhance the reduction in subcutaneouslipid-rich cells. Lipolysis may be enhanced by local cold exposure,inducing stimulation of the sympathetic nervous system.

In certain embodiments, once a desired temperature is achieved, thetemperature of the region can be maintained for a pre-determined periodof time. The cooling cycle can be terminated by separating the heatexchanging surfaces 131 a-b from the skin. After a certain period oftime, the cooling device 104 can be reapplied to the same portion of theskin as described above until a desired reduction in lipid-rich cells isachieved. In another embodiment, the cooling device 104 can be appliedto a different portion of the skin as described above to selectivelyaffect lipid-rich cells in a different subcutaneous target region.

One expected advantage of several of the embodiments described above isthat the cooling device 104 can selectively reduce subcutaneouslipid-rich cells without unacceptably affecting the dermis, epidermisand/or other tissues. Another expected advantage is that the coolingdevice 104 can simultaneously selectively reduce subcutaneous lipid-richcells while providing beneficial effects to the dermis and/or epidermis.These effects may include: fibroplasias, neocollagenesis, collagencontraction, collagen compaction, collagen density increase, collagenremodeling, and acanthosis (epidermal thickening). Another expectedadvantage is that the cooling device 104 can conform to various bodycontours of a subject by rotating the first and second cooling elements130 a-b to achieve a desired orientation. Yet, another expectedadvantage is that the cooling device 104 can be configured as a handhelddevice for ease of operation. Furthermore, another expected advantage isthat the system 100 with the handheld cooling device 104 and the rackmounted processing unit 114 and cooling unit 106 are compact andefficient such that the method described above can be administered in anoutpatient clinic or a doctor's office instead of in a hospital.

E. Cooling Devices with Thermoelectric Cooling Elements

FIG. 4 is a side elevation view of a cooling device 204 in accordancewith another example of the invention. In this example, severalcomponents of the cooling device 204 are similar to the components ofthe cooling device 104 described above. As such, like reference symbolsrefer to like features and components in FIGS. 1-4. In this example, thecooling device 204 includes cooling elements 230 a-b havingthermoelectric cooling elements configured to reduce the temperature ofa subcutaneous region of the subject 101 for selectively affectinglipid-rich cells in the region.

The first cooling element 230 a can include a housing 239 a and aplurality of fluid ports 238 a coupled to the fluid lines 108 a-b. Thefirst cooling element 230 a can also include a first interface member232 a having a first heat exchanging surface 231 a and a first fluidchamber 250 a. The first interface member 232 a can be constructed witha thermally conductive material at the first heat exchanging surface 231a, but the first interface member 232 a can have an insulating portion211 a around the first heat exchanging surface 231 a.

The first cooling element 230 a can further include a thermoelectriccooler 214 a, such as a Peltier-type element, having a first side 213 aand a second side 215 a. The first side 213 a is in thermalcommunication with the first interface member 232 a, and the second side215 a is in thermal communication with the fluid chamber 250 a. Thethermoelectric cooler 214 a can be connected to an external power supply(not shown) to transfer heat between the first side 213 a and the secondside 215 a. The thermoelectric cooler 214 a can be a single Peltier-typeelement or an array of Peltier-type elements. One suitablethermoelectric cooler is a Peltier-type cooling element (model #CP-2895) produced by TE Technologies, Inc. in Traverse City, Mich.

By applying power to the thermoelectric cooler 214 a, heat can beeffectively removed from the subject's skin via the first heatexchanging surface 231 a to a circulating fluid in the fluid chamber 250a. For example, applying a current to the thermoelectric cooler 214 acan achieve a temperature generally below 37° C. on the first side 213 aof the thermoelectric cooler 214 a to remove heat from the subject 101via the first heat exchanging surface 231 a. The thermoelectric cooler214 a transfers the heat from the first side 213 a to the second side215 a where the heat is then transferred to the circulating fluid. Thecooling unit 106 then removes the heat from the circulating fluid.

The thermoelectric coolers 214 a-b can be configured to withdraw asufficient amount of heat quickly from the subject 101 without using ahigh-voltage power supply for the cooling unit 106. In one example, theinterface members 232 a-b can be a generally rectangular aluminum platewith dimensions of about 3 cm×4 cm×1 cm, and the thermoelectric coolersare Peltier-type thermoelectric elements rated at about 160 Watts. Assuch, the cooling device 204 can cool a portion of the subject's skin(approximately 3 cm×4 cm×5 cm) from a temperature of about 37° C. toabout −20° C. quickly and effectively. The cooling unit 106 can use anormal voltage power supply (e.g., 120 VAC) because the powerconsumption is not excessive. This enables the system to be used inhospitals, clinics, and small offices without more costly high voltageelectrical systems.

The cooling device 204 can also be in electrical communication with theprocessing unit 114, and the cooling temperature can be automaticallyadjusted by the processing unit 114. The temperature of the first heatexchanging surface 231 a can be sensed by the sensing element 135 a. Thesensed electrical signal can be converted by the processing unit 114into a process value for the temperature. In one embodiment, theprocessing unit 114 can include a Proportional, Integral and Derivativecontroller, which can adjust the power output to the thermoelectriccooler 214 a to achieve and/or maintain the desired temperature.

F. Cooling Devices with Curved Heat Exchanging Surfaces

FIG. 5 is a side elevation view of a cooling device 304 in accordancewith another example of the invention. Several components of the coolingdevice 304 are similar to those of the cooling device 104. As such, likereference symbols refer to like features and components in FIGS. 1-5. Inthis example, the cooling device 304 includes cooling elements 330 a-bwith curved heat exchanging surfaces 331 a-b as described in more detailbelow.

The first cooling element 330 a can include a housing 339 a, a fluidchamber 350 a, and fluid ports 338 a coupled to the fluid lines 108 a-b.The first cooling element 330 a can further include an interface member332 a having a curved heat exchanging surface 331 a and a back surface333 a. The curved heat exchanging surface 331 a can be either concave orconvex, and the back surface 333 a can be either generally planar orsimilarly curved as the heat exchanging surface 331 a. The first coolingelement 330 a can further include a thermoelectric cooler 314 aproximate to the back surface 333 a and in thermal communication withthe fluid chamber 350 a for removing heat via the heat exchangingsurface 331 a.

The second cooling element 330 b in FIG. 5 includes similar features asthe first cooling element 330 a. Specifically, the second coolingelement 330 b includes a concave heat exchanging surface 331 b withgenerally the same curvature as that of the heat exchanging surface 331a. However, the second cooling element 330 b can also have a heatexchanging surface 331 b that is concave but with a different curvaturefrom that of the first heat exchanging surface 331 a, or the heatexchanging surface 331 b can be generally planar or convex. As such, thefirst and second heat exchanging surfaces 331 a-b can have anycombination of the different surface curvatures.

The first and second heat exchanging surfaces 331 a-b operate generallysimilarly to the heat exchanging surfaces 131 a-b of the cooling device104. Particularly, the two curved first and second heat exchangingsurfaces 331 a-b can transfer heat to/from a portion of the skin whenthe portion of the skin is placed proximate to the first and second heatexchanging surfaces 331 a-b. The curved surfaces 331 a-b can enhanceheat transfer from the portion of the skin as described below in moredetail.

In operation, the cooling device 304 can be placed proximate to the skinof the subject 101 such that a portion of the skin is placed against thetwo curved heat exchanging surfaces 331 a-b. Then the portion of theskin can be either clamped, strapped or pressed as described above withreference to FIGS. 2 and 3. In one embodiment, a voltage is applied tothe thermoelectric coolers 314 a-b to cool a subcutaneous region of thepatient as described above with reference to FIG. 4. In furtherembodiments, other cooling methods can also be used, such as byconvection, radiation, conduction, or any combination of these methods.

One advantage of the curved heat exchanging surfaces 331 a-b is that thecurved surfaces may focus the heat transfer in the subcutaneous region.For example, when both the heat exchanging surfaces are concave, theconcave surfaces can focus heat removal from the skin between the twoheat exchanging surfaces 331 a-b. When both the heat exchanging surfacesare convex, the convex surfaces can spread the skin between the two heatexchanging surfaces 331 a-b such that the distance between thesubcutaneous layer of the skin and the heat exchanging surfaces 331 a-bis reduced. The reduced distance may enhance heat transfer because thethermal conductivity of the epidermis and dermis decreases withdecreased thickness.

G. Computing System Software Modules

FIG. 6 illustrates a functional diagram showing exemplary softwaremodules 440 suitable for use in the processing unit 114. Each componentcan be a computer program, procedure, or process written as source codein a conventional programming language, such as the C++ programminglanguage, and can be presented for execution by the CPU of processor442. The various implementations of the source code and object and bytecodes can be stored on a computer-readable storage medium or embodied ona transmission medium in a carrier wave. The modules of processor 442can include an input module 444, a database module 446, a process module448, an output module 450, and optionally, a display module 451. Inanother embodiment, the software modules 440 can be presented forexecution by the CPU of a network server in a distributed computingscheme.

In operation, the input module 444 accepts an operator input, such asprocess setpoint and control selections, and communicates the acceptedinformation or selections to other components for further processing.The database module 446 organizes records, including operatingparameters 454, operator activities 456, and alarms 458, and facilitatesstoring and retrieving of these records to and from a database 452. Anytype of database organization can be utilized, including a flat filesystem, hierarchical database, relational database, or distributeddatabase, such as provided by a database vendor such as OracleCorporation, Redwood Shores, Calif.

The process module 448 generates control variables based on the sensorreadings 456, and the output module 450 generates output signals 458based on the control variables. For example, the output module 450 canconvert the generated control variables from the process module 448 into4-20 mA output signals 458 suitable for a direct current voltagemodulator. The processor 442 optionally can include the display module451 for displaying, printing, or downloading the sensor readings 456 andoutput 458 via devices such as the output device 120. A suitable displaymodule 451 can be a video driver that enables the processor 442 todisplay the sensor readings 456 on the output device 120.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number respectively. When the claims usethe word “or” in reference to a list of two or more items, that wordcovers all of the following interpretations of the word: any of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

The above detailed descriptions of embodiments of the invention are notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whilesteps are presented in a given order, alternative embodiments mayperform steps in a different order. The various embodiments describedherein can be combined to provide further embodiments.

In general, the terms used in the following claims should not beconstrued to limit the invention to the specific embodiments disclosedin the specification, unless the above detailed description explicitlydefines such terms. While certain aspects of the invention are presentedbelow in certain claim forms, the inventors contemplate the variousaspects of the invention in any number of claim forms. Accordingly, theinventors reserve the right to add additional claims after filing theapplication to pursue such additional claim forms for other aspects ofthe invention.

1. A method of applying a cooling device having two cooling elementsrotatable relative to each other, the cooling elements having opposingspaced apart heat exchanging surfaces for removing heat from a subjecthaving skin, wherein at least one of the heat exchanging surfaces isconvex or concave, the method comprising: (i) rotating at least one ofthe cooling elements to achieve a desired orientation between the twoheat exchanging surfaces; (ii) cooling the heat exchanging surfaces ofthe two cooling elements to a desired temperature; (iii) placing thecooled heat exchanging surfaces in the desired orientation relative tothe skin of the subject; and (iv) reducing a temperature of a regionunder the epidermis of the patient such that lipid-rich cells in theregion are affected while non-lipid-rich cells in the epidermis are notaffected.
 2. The method of claim 1, wherein the desired temperature isbetween about −20° C. to about 10° C.
 3. The method of claim 1, furthercomprising maintaining the heat exchanging surfaces of the two coolingelements at the desired temperature.
 4. The method of claim 1, whereinplacing the cooled surfaces of the two cooling elements relative to theskin of the subject comprises clamping the skin between the two coolingelements.
 5. The method of claim 1, wherein placing the cooled surfacesof the two cooling elements relative to the skin of the subjectcomprises pressing a region of the skin with the two cooling elements toapply a pressure greater than or equal to a systolic blood pressure inthe skin.
 6. The method of claim 1, wherein one the cooling elementsincludes a sensing element, and wherein the method further comprisesmonitoring an operating parameter via the sensing element.
 7. The methodof claim 6, wherein the sensing element is a temperature sensing elementand the operating parameter is a temperature, and wherein the methodfurther comprises adjusting a heat removal rate from at least one of thetwo cooling elements based on the monitored temperature.
 8. The methodof claim 1, wherein one of the cooling elements includes athermoelectric cooling element in thermal communication with acorresponding heat exchanging surface, and wherein cooling the heatexchanging surfaces comprises applying a voltage to the thermoelectriccooling element to remove heat from the corresponding heat exchangingsurface.
 9. The method of claim 1, further comprising: terminatingtemperature reduction of the region by removing the cooling elementsfrom the region; and repeating stages (i)-(iv) until a desired reductionin lipid-rich cells of the region is achieved.
 10. The method of claim1, further comprising: affecting lipid-rich cells of a first region ofthe subject by performing stages (i)-(iv) at the first region; andaffecting lipid-rich cells of a second region of the subject byperforming stages (i)-(iv) at the second region.
 11. A method ofapplying a handheld cooling device configured to be grasped by a hand ofan operator, the cooling device having two opposing spaced apart coolingelements configured for removing heat from subcutaneous lipid-richcells, each cooling element having a heat exchanging surface, whereinone or both of the heat exchanging surfaces are concave or convex, themethod comprising: (i) rotating the two cooling elements relative toeach other; (ii) cooling the heat exchanging surfaces of the two coolingelements to a desired temperature; (iii) holding the cooling device by ahand; (iv) placing the cooling device such that the cooled heatexchanging surfaces are proximate to the skin of a subject; and (v)reducing a temperature of a region under the epidermis of the subjectsuch that lipid-rich cells in the region of the skin are affected whilenon-lipid-rich cells in the epidermis are not affected.
 12. The methodof claim 11, wherein placing the cooled surfaces of the two coolingelements comprises clamping the skin between the two cooling elements.13. The method of claim 12, wherein the handheld cooling device furthercomprises an actuator for adjusting a clamping pressure between the twocooling elements, and wherein clamping the subject's skin furthercomprises adjusting the clamping pressure between the two coolingelements with the actuator.
 14. The method of claim 11, wherein placingthe cooled surfaces of the two cooling elements comprises pressing thetwo cooling elements against the skin to apply a pressure greater thanor equal to a systolic blood pressure in skin.
 15. The method of claim11, wherein positioning the two cooling elements comprises moving thetwo cooling elements in at least one of (a) a direction linearlyrelative to each other and (b) rotatable relative to each other, andwherein placing the cooling device further comprises adjusting at leastone of the two cooling elements to generally conform to a body contourof the subject.
 16. The method of claim 11, wherein one of the coolingelements includes a thermoelectric cooling element in thermalcommunication with a corresponding heat exchanging surface, and whereincooling the heat exchanging surfaces comprises applying a voltage to thethermoelectric cooling element to remove heat from a corresponding heatexchanging surface.
 17. The method of claim 16, wherein at least one ofthe cooling elements further comprises a fluid chamber in thermalcommunication with the thermoelectric cooling element, wherein themethod further comprises circulating a coolant through the fluidchamber.
 18. The method of claim 11, further comprising: terminatingtemperature reduction of the region by removing the cooling device fromthe region; and repeating stages (i)-(v) until a desired reduction inlipid-rich cells of the region is achieved.
 19. The method of claim 11,further comprising: affecting lipid-rich cells of a first region of thesubject by performing stages (i)-(v) at the first region; and affectinglipid-rich cells of a second region of the subject by performing stages(i)-(v) at the second region.
 20. A method of applying a cooling deviceto a subject having skin, the method comprising: positioning a firstcooling element of the cooling device to be spaced apart from a secondcooling element of the cooling device, each of the first and secondcooling elements having a heat exchanging surface for removing heat fromthe subject, wherein at least one of the heat exchanging surfaces isconvex or concave; cooling the heat exchanging surfaces of the first andsecond cooling elements to a predetermined temperature; positioning afold of the subject's skin between the heat exchanging surfaces;rotating at least one of the first and second cooling elements relativeto the other cooling element with the fold of the subject's skin betweenthe heat exchanging surfaces; and reducing a temperature of a regionwithin the fold of the subject's skin such that lipid-rich cells in theregion are affected while non-lipid-rich cells in the skin are notaffected.
 21. The method of claim 20 wherein rotating at least one ofthe first and second cooling elements comprises applying pressure to thefold of the subject's skin that is generally equal to or greater than asystolic blood pressure in the fold of the subject's skin.
 22. Themethod of claim 20, further comprising: monitoring a pressure in thefold of the subject's skin; and wherein rotating at least one of thefirst and second cooling elements further comprises rotating at leastone of the first and second cooling elements relative to the othercooling element in response to the pressure in the fold of the subject'sskin.
 23. The method of claim 20 wherein rotating at least one of thefirst and second cooling elements comprises adjusting a relativeposition between the heat exchanging surfaces to accommodate a contourof the fold of the subject's skin.
 24. The method of claim 20 whereinrotating at least one of the first and second cooling elements comprisesadjusting the heat exchanging surface of the first cooling element to beoriented at a non-zero angle relative to the heat exchanging surface ofthe second cooling element.